Tuesday, 1 December 2009

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Hubble Explains Nebula’s Ruddy Complexion

Posted: 01 Dec 2009 09:51 AM PST


A ruddy nebula reflects the light from a huge, nearby star in this latest image released by the Hubble Space Telescope's operators.

The Iris Nebula is a bit mysterious. It's not hot enough to emit its own light, like some nebulae do. Instead, the Iris reflects light from the star, HD 200775, which is 10 times as massive as the sun, Most nebulae of this type are blue-tinged, but as you can see, it's obviously reddish. Why?

By studying the dust's composition, astronomers have discovered that the filaments above and to the left of the image's center are red because of an unknown chemical, likely hydrocarbon based. They're now working to figure out what the exact compound is.

The study of objects like the Iris, which is located about 1,400 light-years away in the Cephelus constellation, have come a long way since Sir William Herschel first discovered it in 1794. Not only can the Hubble's Advanced Camera for Surveys provide amazing detail, but Hubble's Near Infrared Camera and Multi-Object Spectrometer can be used to analyze the chemical makeup of celestial bodies.

Zoomed out farther, the composite image below shows exactly why the Iris Nebula is so named.

Image: NASA & ESA. High-resolution images.


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Loneliness May Be Contagious

Posted: 01 Dec 2009 08:50 AM PST


Staying socially connected may be just as important for public health as washing your hands and covering your cough. A new study suggests that feelings of loneliness can spread through social networks like the common cold.

sciencenews"People on the edge of the network spread their loneliness to others and then cut their ties," says Nicholas Christakis of Harvard Medical School in Boston, a coauthor of the new study in the December Journal of Personality and Social Psychology. "It's like the edge of a sweater: You start pulling at it and it unravels the network."

This study is the latest in a series that Christakis and James Fowler of the University of California, San Diego have conducted to see how habits and feelings move through social networks. Their earlier studies suggested that obesity, smoking and happiness are contagious.

The new study, led by John Cacioppo of the University of Chicago, found that loneliness is catching as well, possibly because lonely people don't trust their connections and foster that mistrust in others.

Loneliness appears to be easier to catch from friends than from family, to spread more among women than men, and to be most contagious among neighbors who live within a mile of each other. The study also found that loneliness can spread to three degrees of separation, as in the studies of obesity, smoking and happiness. One lonely friend makes you 40 to 65 percent more likely to be lonely, but a lonely friend-of-a-friend increases your chances of loneliness by 14 to 36 percent. A friend-of-a-friend-of-a-friend adds between 6 and 26 percent, the study suggests.

Not all networks researchers are convinced. Jason Fletcher of the Yale School of Public Health says that the studies' controls are not good enough to eliminate other explanations, like environmental influences or the tendency of similar people to befriend each other. Fletcher has published a study (in the same issue of the British Medical Journal that reported that happiness is contagious) showing that acne, headaches and height also appear to spread through networks even though they are not likely to be transmitted socially.

"We're on the side that [social contagion] exists — we're not naysayers," Fletcher says. "We just think the evidence isn't clear enough on many of the outcomes."

Despite its shortcomings, some researchers are enthusiastic about the study.

"I think this is a groundbreaking paper in loneliness literature," says Dan Perlman, a psychologist at the University of North Carolina at Greensboro who specializes in loneliness. "Maybe there are people who are skeptical, but this is important work. I think that it should get a pat on the back."

Christakis and Fowler examined data from a long-term health study based in Framingham, Mass., a small town where many of the study's participants knew each other. The Framingham study followed thousands of people over 60 years, keeping track of physical and mental heath, habits and diet.

Each participant also named friends, relatives and neighbors who might know where they would be in two years, when it was time for the next exam. From this information, Christakis and Fowler reconstructed the social network of Framingham, including more than 12,000 ties between 5,124 people. The researchers plotted how reported loneliness, measured via a diagnostic test for depression, changed over time.

The results indicate that lonely people tend to move to the peripheries of social networks. But first, lonely people transmit their feeling of isolation to friends and neighbors.

Feeling lonely doesn't mean you have no connections, Cacioppo says. It only means those connections aren't satisfying enough. Loneliness can start as a sense that the world is hostile, which then becomes a self-fulfilling prophecy.

"Loneliness causes people to be alert for social threats," Cacioppo says. "You engage in more self-protective behavior, which is paradoxically self-defeating." Lonely people can become standoffish and eventually withdraw from their social networks, leaving their former friends less well-connected and more likely to mistrust the world themselves.

Because loneliness is implicated in health problems from Alzheimer's to heart disease, Cacioppo says, reconnecting to those who have fallen off the network may be vital for public health.

Image: Flickr/Julie70

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There’s No Such Thing as a ‘Simple’ Organism

Posted: 30 Nov 2009 02:15 PM PST


What may be the most thorough study ever of a single organism has produced a beta code for life's essential subroutines, and shown that even the simplest creatures are more complex than scientists suspected.

The analysis combined information about gene regulation, protein production and cell structure in Mycoplasma pneumoniae, one of the simplest self-sustaining microbes.

It's far closer to a "blueprint" than a mere genome readout, and reveals processes "that are much more subtle and intricate than were previously considered possible in bacteria," wrote University of Arizona biologists Howard Ochman and Rahul Raghavan in a commentary accompanying the findings, which were published last Thursday in Science.

M. pneumoniae has just one-fifth as many genes as E. coli, the traditional single-cell model organism. That makes it an ideal target for systems biologists who want to understand how cells function. To them, genome scans are just a first step. They don't explain when or why genes are turned on and off, or how different genes interact at different times, or how cellular "machines" use proteins produced by gene instructions.

In the new studies, German and Spanish researchers documented almost every single protein used by M. pneumoniae. They looked up the known functions of each of its genes, and made recordings of gene activity. They documented all the chemical reactions inside M. pneumoniae and mapped its physical structure. Then they put all this together.

What emerged was a picture of surprising complexity. M. pneumoniae needs just eight gene "switches" to control its molecular activities, compared to 50 in E. coli — a number so low that it implies other, as-yet-unknown regulatory processes. Groups of genes thought to work in unison did so only intermittently. At other times they worked in isolation, or in unexpected configurations.

The findings also showed that chromosome topography — the actual, three-dimensional arrangement of an operating genome, rather than its linear laboratory readout — plays an important part in determining how genes interact.

In short, there was a lot going on in lowly, supposedly simple M. pneumoniae, and much of it is beyond the grasp of what's now known about cell function.

Eventually, the thorough analytical approach used to study M. pneumoniae could be applied to other microbes. The findings could also be used by synthetic biologists trying to synthesize microbial life. But for now, they show just how much work remains to be done before life's essential processes are understood.

"Linear mapping of genes to function rarely considers how a cell actually accomplishes the processes," wrote Ochman and Raghavan. "There is no such thing as a 'simple' bacterium."

Image: From Science, a 3-D reconstruction (left) of the M. pneumoniae cell; a map (right) of interactions between the amino-acid–making ribosome and the cell's proteins.

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Citations: "Proteome Organization in a Genome-Reduced Bacterium." By Sebastian Kühner, Veravan Noort, Matthew J. Betts, Alejandra Leo-Macias, Claire Batisse, Michaela Rode, Takuji Yamada, Tobias Maier, Samuel Bader, Pedro Beltran-Alvarez, Daniel Castaño-Diez, Wei-Hua Chen, Damien Devos, Marc Güell, Tomas Norambuena, Ines Racke, Vladimir Rybin, Alexander Schmidt, Eva Yus, Ruedi Aebersold, Richard Herrmann, Bettina Böttcher, Achilleas S. Frangakis, Robert B. Russell, Luis Serrano, Peer Bork, Anne-Claude Gavin. Science, Vol. 326 Issue 5957, Nov. 27, 2009.

"Transcriptome Complexity in a Genome-Reduced Bacterium." By Marc Güell, Vera van Noort, Eva Yus, Wei-Hua Chen, Justine Leigh-Bell, Konstantinos Michalodimitrakis, Takuji Yamada, Manimozhiyan Arumugam, Tobias Doerks, Sebastian Kühner, Michaela Rode, Mikita Suyama, Sabine Schmidt, Anne-Claude Gavin, Peer Bork and Luis Serrano. Science, Vol. 326 Issue 5957, Nov. 27, 2009.

"Impact of Genome Reduction on Bacterial Metabolism and Its Regulation." By Eva Yus, Tobias Maier, Konstantinos Michalodimitrakis, Vera van Noort, Takuji Yamada, Wei-Hua Chen, Judith A. H. Wodke, Marc Güell, Sira Martínez, Ronan Bourgeois, Sebastian Kühner, Emanuele Raineri, Ivica Letunic, Olga V. Kalinina, Michaela Rode, Richard Herrmann, Ricardo Gutiérrez-Gallego, Robert B. Russell, Anne-Claude Gavin, Peer Bork and Luis Serrano. Science, Vol. 326 Issue 5957, Nov. 27, 2009.

"Excavating the Functional Landscape of Bacterial Cells." By Howard Ochman and Rahul Raghavan. Science, Vol. 326 Issue 5957, Nov. 27, 2009.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecosystem and planetary tipping points.

Kiwi Rocket Scares Sheep, Reaches Space

Posted: 30 Nov 2009 12:49 PM PST

A small, private company launched New Zealand's first rocket into space to cheers from about 50 people gathered on a small island off the country's coast.

atea-1-new-zealandAs the noise of the blastoff sent sheep running, the 18-foot rocket raced into the sky, reaching beyond the Kármán line, 100 kilometers (62 miles) above the Earth's surface, which is traditionally considered the dividing altitude between the upper atmosphere and real space.

The Atea-1, named after the Maori word for space, was built by Rocket Lab. It's the first privately built rocket launched from the Southern Hemisphere to reach space.

"It's not trivial sending something into space," Mark Rocket, Rocket Lab director and former Internet entrepreneur, told local media. "This is a huge technological leap for New Zealand."

After the sub-orbital vehicle entered space, it turned back toward Earth and splashed down. The Rocket Lab team is currently trying to locate the rocket, which was expected to fall into the Pacific Ocean about 30 miles northeast of Great Mercury Island, a privately owned resort and the rocket's takeoff point.

If you happen to be in the area and see the payload, don't go scooping it up, Rocket Lab warned through its Twitter feed.

"IMPORTANT: Marine traffic in the Coromandel, do not recover payload, it contains delicate scientific instruments & is potentially hazardous," the Lab wrote. "If found please mark the payload location, and relay the GPS coordinates to Rocket Lab ASAP."

The Atea-1 is unusually light and small. Including propellant, the 18-foot rocket weighs less than 150 pounds. It's built largely from carbon fiber composites and its 30-pound engine generates thrust equivalent to 3,200 horsepower. The Atea can take payloads of up to about four and a half pounds.

By comparison, an Atlas V rocket weighs 1.2 million pounds and can carry payloads of 65,000 pounds to low-earth orbit.

Video: TVNZ. Image: Rocket Lab.

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WiSci 2.0: Alexis Madrigal's Twitter, Google Reader feed, and green tech history research site; Wired Science on Twitter and Facebook.

Naked Black Hole Builds Future Galactic Dream Home

Posted: 30 Nov 2009 09:57 AM PST


Astronomers have captured a distant black hole creating the galaxy that will eventually become its home.

By sending a jet of gas and highly energetic particles into a neighboring galaxy, the black hole has touched off star formation at a rate 100 times the galactic average.

"Our study suggests that supermassive black holes can trigger the formation of stars, thus 'building' their own host galaxies," David Elbaz, lead author of a paper on the work in the journal Astronomy and Astrophysics, said in a press release. "This link could also explain why galaxies hosting larger black holes have more stars."

phot-46b-09-fullresThe quasar HE0450-2958, located about 5 billion light-years from Earth, is powered by a supermassive black hole. Unlike all other known quasars, this one did not appear to be surrounded by a galaxy, which had puzzled astronomers. They thought perhaps the quasar's surrounding galaxy was obscured by dust.

So, in the latest observations they looked in the mid-infrared part of the spectrum, in which dust shines brightly, using the European Southern Observatory's Very Large Telescope. But they didn't see dust, confirming the idea that the quasar really is "naked."

Instead of a surrounding galaxy, Elbaz's team found the black hole was blasting its neighbor with energy and matter. That injection has caused the observed flurry of star births: 350 new suns are bursting into existence each year in the region.

Eventually, the black hole will merge with its neighbor. The two objects are located 22,000 light-years apart and are moving towards each other at less than 125 miles per second. In tens of millions of years, HE0450-2958 will finally get a home.

"This would provide a natural explanation for the missing host galaxy," Elbaz and his co-authors wrote.

Images: 1) Artist's rendering of HE450-2958 and its galactic neighbor.
2) Composite image of HE450-2958 composed of imagery from Hubble, Very Large Telescope, and the Advanced Camera for Surveys.

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WiSci 2.0: Alexis Madrigal's Twitter, Google Reader feed, and green tech history research site; Wired Science on Twitter and Facebook.

How to Mix Oil and Water

Posted: 30 Nov 2009 08:35 AM PST


Scientists in Belgium have uncovered a new way to shake things up. Violent bouncing of a water droplet coated with oil causes the oil layer to move inside and fracture into many oily globs. In a paper published in the December Chaos, researchers at the University of Liège in Belgium call this microemulsion of oil and water the mayonnaise droplet.

sciencenewsFrom earlier experiments, researchers knew that oily droplets bounce several times on a bed of oil before merging with the oil base. But Denis Terwagne and colleagues wanted to know what would happen to an oil-coated water droplet if the bouncing was prolonged. To find out, the team constructed a moving base that would quickly raise and lower the oil bed, similar to using a horizontal Ping-Pong paddle to keep a ball bouncing.

oil_water_mixWhen the oil-coated water droplet hit the oil surface and deformed, some of the outer oil layer was ushered into the interior of the droplet. Subsequent bounces shattered this interior oil glob, creating a thoroughly mixed oil-in-water-in oil droplet, the researchers found.

Understanding the forces that govern the mayonnaise droplet may help scientists design new microfluidic systems. Bouncing droplets could enable more efficient ways to create complex mixtures of liquids, such as for cosmetics or pharmaceuticals.

Images: 1) Flickr/jordi.martorell2) D. Terwagne et al./Chaos 2009

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